Hello everyone-

As Paul already heard, today was supposed to be  the triumphant email
announcing 1st flight of the PPort  engine.

Unfortunately, we had a mishap during a landback  test.

We're still going through a fault analysis to figure out  exactly what
happened, but a couple things clearly conspired to ruin  our day.  The
engine
ran like gangbusters and accelerated  the airplane quicker than expected.
The airplane flew itself up off  the runway before the pilot was quite
ready.  Climb attitude  pitch was too high, letting the airplane quickly
climb up out of  ground effect.  Retarding the throttle caused the engine
to
stumble and lose power for unknown reason.  Left wing stalled above  ground
effect.

All in all, it was a rather more  exciting afternoon than we'd really hoped
for.

The  good news is that despite a recipe for disaster, the damage to the
airplane appears minor.  We'll need a new port aileron from when the  left
tip of the wing dragged on the ground, and the mains &  engine mount will
need some close inspection to make sure they're in  as good shape as they
appear to be.  The prop does not look  like it hit any dirt.  And the
engine
started and ran ran  fine during the taxi back to the hangar.  We cycled
the
engine though the full rpm range, including max-static when we got  the
airplane back & saw no issues.

We have two  working ideas on why the engine might have stumbled during the

land back attempt.  First is a fuel-flow issue due to the  nose-high
attitude.  We'll test for this by putting the mains  on ramps and trying to
bring the engine to full power.  If we  have a fuel flow issue, this should
highlight it.  The second  idea is that our engine mapping is the cause.
During our ground  runs, we have many map addresses which we can never get
to.   Thus we do not have values in these addresses.  Perhaps the  engine
entered this address range and thus  stumbled.



Mark (Rocky Mtn  High)

Mark,

Sorry to hear about the mishap.  My friend had  somthing similar happen
during his first flight in a Midget Mustang with an  O- 200.  Turned out to
be a bad carb that went full rich as he got  airborn.  He has it all
together
an completly re built the Continental  and we just ran it at full throttle
on
a set of ramps.

Joe  Berki

Mark,

I too am sorry to hear about your mishap. It is a very painful thing to go
through after all of the work, blood, sweat and tears that go into a
project.  I'm glad that the damage was "minor"(no such thing).

With regard to fuel flow, I believe that just checking if t he engine will
run at full power at take off attitude overlooks the necessity to test fuel
flow  to at least 125% of max fuel burn of the engine when in takeoff
attitude for a  pumped system and greater fuel flow for a gravity feed system. It
is doubtful  that it is a fuel flow situation, however.

Is your air intake in a place common to that of other craft of you type. Is
it possible that a combination of attitude and airflow (possibly negative
pressure at the intake) caused this. Did you test the engine response, on
the  ground for throttle response in this situation. Was the throttle slam
retarded  or slowly retarded (in the anxiety)?

Again my sympathies go out to you.

Rich